Poster 58: Reduced hip extension in the elderly: dynamic or postural?

Objective: To determine whether reduced hip extension and increased anterior pelvic tilt are dynamic gait phenomena that do not occur during normal standing posture. Design: Experiment. Setting: Gait laboratory. Participants: 25 elderly subjects (age, 71±4.7y) compared with 25 young adult subjects (age, 26±4.6y). Interventions: Subjects were observed during standing and walking at specific speeds while positions and kinematics of pelvics and lower extremities were measured using a 3-dimnesional optoelectronic analysis system. Main Outcome Measures: Peak hip extension and anterior pelvic tilt. Results: There were no statistically significant differences between the elderly and young adult groups during standing with respect to either mean hip extension (2.7° vs 1.5°, respectively, P=.43) or mean anterior pelvic tilt (10.6° vs 10.4°, P=.85). On the other hand, consistent with prior studies, peak hip extension was significantly reduced and anterior pelvic tilt was increased in elderly subjects at all walking speeds compared with younger subjects (P<.05 at all 3 walking speeds). Conclusions: Age-related changes in gait, characterized by reduced peak hip extension and increased anterior pelvic tilt, are dynamic rather than standing postural processes.